OZARK, Miss. (AP) - Authorities in Mississippi said they are searching for the chief person of interest in the investigation of poisoned letters sent to President Barack Obama and other officials. ItawambaMore >>

Authorities have searched a Mississippi home in an ongoing investigation into a Tupelo man considered a person of interest in the mailing of tainted letters to President Barack Obama and Sen. Roger Wicker.More >>

James Everett Dutschke, 41, entered his plea at a hearing in Oxford. As part of the plea agreement, he will serve a 25 year prison sentence.

Specifically, Dutschke pleaded guilty to developing and possessing the biological agent, ricin, and then mailing the ricin-laced, threatening letters to President Barack Obama, U.S. Senator Roger Wicker, and a Tupelo, Miss. judge.

But despite his plea, he still addressed members of the media in the courtroom Friday and said, "I'm still not guilty."

If the judge accepts his plea, Dutschke will go to jail for 25 years. The judge is expected to sentence him in approximately 60 days.

The letter reportedly went out in April 2013 in an attempt to retaliate and frame another man, according to court documents.

Investigators found traces of ricin when they searched Dutschke's trash, as well as inside his Taekwondo studio.

In a Federal Bureau of Investigation affidavit made public following the arrest, it was revealed that Dutschke bought castor beans on the Internet from vendors on eBay and PayPal in order to make the poison.

Dutschke's attorney said testimony about how toxic the ingredients were could have sent his client to jail for life, which is why they decided to plead out.

"Depending on whose experts you believe and whether the substance was toxic or not, it's the difference in a life sentence and a sentence that would have been less than 25 years, so this was right in the middle," said Defense Attorney Kenneth Coughlin.

The ricin letter arrest was not Dutschke's first brush with the law. He was also arrested after being accused of exposing himself to young girls in his neighborhood.

"I'm very eager to clear my name," James Everett Dutschke said in January 2013. "This small mole hill has been blown way out of proportion."

He was convicted in February 2013 of indecent exposure and sentenced to 90 days behind bars.